1. Field of the Invention
The present invention relates to a reactive black dye composition for cellulose fiber and more particularly, to the reactive black dye composition with excellent several fastnesses, dyeing levelness, reproducibility and dyeing yield, comprising a mixture with a certain amount ratio of an orange reactive dye expressed in the following formula 1 and black dye expressed in the following formula 2: 
wherein Z is xe2x80x94OSO3M or OC(O)CH3; and M is an alkaline metal atom.
2. Description of the Related Art
A black dye is the most frequently consumed dyes of all dyes. Most of black dyes are employed as a mixture of several dyes rather than alone. likewise, the black dye is the most applicable one as reactive dye and most of black dye for cellulose fiber on the market is a mixture of C. I. Reactive Black 5 represented in the following formula 2a and orange dye: 
However, vinylsulfone-based orange dye used for mixing colors to prepare the black dye has low several fastnesses, especially light fastness and poor fixation relative to other dyes, which results in wastefulness and difficulty in adjusting tone.
In an effort to overcome aforementioned problems of vinylsulfone-based orange dye used for mixing colors to prepare the black dye, the inventors have researched to synthesize a novel orange dye. As a result, they provided a orange reactive dye expressed in the above formula (1), which shows not only enhanced several fastnesses such as light fastness, washing fastness, perspiration fastness and chlorine fastness but also better dyeing yield relative to other orange dyes with mono-reactive group.
The inventors completed this invention in such a manner that the novel orange reactive dye expressed in the above formula (1), which is synthesized by the inventors and the conventional black reactive dye expressed in the above formula (2) are mixed in a certain amount ratio, thereby reducing wastefulness of dye due to higher fixation of the orange reactive dye and improving several fastnesses such as light fastness during dyeing of cellulose fiber, in addition to feasibility of mixing colors.
Accordingly, an object of this invention is to provide a reactive black dye composition for cellulose fiber having excellent several fastnesses, dyeing levelness, reproducibility and dyeing yield
This invention is characterized by a reactive black dye composition for cellulose fiber comprising a mixture in which an orange reactive dye expressed in the following formula 1 and black dye expressed in the following formula 2 is mixed in the range of 15-35 wt %: 65-85 wt %: 
wherein Z is xe2x80x94OSO3M or OC(O)CH3; and M is an alkaline metal atom.
This invention is explained in more detail as set forth:
The reactive black dye composition of this invention is prepared in such a manner that the black dye expressed in the formula 2 is mixed with the orange reactive dye expressed in the formula 1 in a certain amount ratio and thus leads to excellent color yield, property of build-up, reproducibility, dyeing levelness and several fastnesses, especially feasibility of mixing due to lower wastefulness of orange dye during washing.
The process for preparing the novel orange reactive dye is expressed as the following Scheme 1: 
wherein M is an alkaline metal atom; Z is xe2x80x94OSO3M or OC(O)CH3; and R is alkyl group having 1-4 of carbon atom.
The process for preparing the orange reactive dye represented in the above Scheme 1 is as follows:
First, aminophenyl-xcex2-ethylsulfone derivative is diazo nated. In addition, alkyl chloroformate is slowly added to neutralized solution of 6(7)-amino4-hydroxy-2-naphthalene sulfonic acid at 0-25xc2x0 C. in the presence of LiOH or Li2CO3 for adjusting pH to be 3-6, which leads to condensation reaction, thus preparing 6(7)-alkoxycarbonylamino-4-hydroxy-2-naphthalene sulfonic acid.
Then, the diazo solution and the condensation solution are mixed at 0-5xc2x0 C., after which the mixture is subjected to coupling reaction with the addition of base to adjust pH to be lower than 6.5, finally preparing vinylsulfone-based orange reactive dye.
Among the black dye used in the composition of this invention, the black dye expressed in the following formula 2a of which Z is xe2x80x94OSO3Na, has been commercialized by many companies since REMAZOL Black B(trademark)(Hoechst, German) was on the market in 1960s. 
Further, the black dye expressed in the following formula 2b of which Z is xe2x80x94OCOCH3, is novel one prepared by the inventors. 
wherein M is an alkaline metal atom.
The process for preparing the novel black reactive dye is expressed as the following Scheme 2: 
wherein M is an alkaline metal atom.
The process for preparing the black reactive dye represented in the above Scheme 2 is as follows:
First, aminophenyl-xcex2-acetoxyethylsulfone derivative is diazo tized. In addition, 1-naphthol-8-amino-3,6-disulfonic acid is neutralized with a base. Then, the diazo solution and the condensation solution are mixed at 0-5xc2x0 C., after which the mixture is agitated with the addition of base to adjust pH to be lower than 7, finally preparing black reactive dye represented in the above formula 2b.
The reactive black dye composition of this invention comprises a mixture in which the orange reactive dye expressed in the following formula 1 and black dye expressed in the following formula 2 is mixed in the range of 15-35 wt % : 65-85 wt %, more preferably in the range of 20-30 wt % : 70-80 wt %. If the amount of the orange reactive dye is lower than 15 wt %, the dye composition becomes bluish black; in the case of exceeding 35 wt %, the dye composition yellowish black.
In addition, if deemed necessary the reactive black dye composition of this invention further includes inorganic salt such as sodium sulfonate and sodium chloride; dispersant; agent of inhibition of raising dust; pH stabilizer; sequestering agent for water such as polyphosphate; and other conventional dye preparation.
The reactive black dye composition of this invention shows excellent color yield, property of build-up, reproducibility and so on. Further to this, dyed fabric with the reactive black dye composition of this invention exhibits excellent several fastnesses such as light fastness, washing fastness, perspiration fastness and chlorine fastness and feasibility of mixing due to lower wastefulness of orange dye during washing.